000
AXNT20 KNHC 111749
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST FRI MAR 11 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF 
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE 
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE 
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND 
RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGE THROUGH 
1730 UTC.

...THE ITCZ...

THE ITCZ IS ANALYZED FROM WESTERN IVORY COAST NEAR 5N6W ALONG 
2N15W TO S OF THE EQUATOR NEAR 24W TO NE BRAZIL NEAR 3N42W. 
SCATTERED MODERATE TO ISOLATED STRONG IS WITHIN 190 NM N OF THE 
AXIS. SIMILAR ACTIVITY IS OCCURRING WITHIN 130 NM OF THE COAST 
OF BRAZIL BETWEEN 35W AND 45W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE AND SINKING AIR 
ALOFT. AT SURFACE...ANTICYCLONIC LIGHT TO MODERATE WINDS ARE 
ACROSS THE BASIN...ANCHORED BY A 1028 MB HIGH OVER SOUTHERN 
LOUISIANA. THIS FLOW IS BRINGING A COOLER AIR MASS TO THE GULF. 
OVER THE NEXT 24 HOURS...THE SURFACE RIDGE WILL DRIFT EAST WITH 
NO OTHER SIGNIFICANT CHANGES EXPECTED DURING THE FORECAST PERIOD.

CARIBBEAN SEA...
A DRY AND STABLE ATMOSPHERE REMAINS ALOFT ACROSS THE CARIBBEAN 
SEA THIS AFTERNOON...EXCEPT THE NW BASIN...DUE TO THE PASSAGE OF 
AN UPPER LEVEL TROUGH THAT SUPPORTS A COLD FRONT THAT ENTERS THE 
AREA FROM CENTRAL CUBA EXTENDING TO BELIZE ALONG 22N79W 20N83W 
16N89W. SCATTERED SHOWERS ARE S OF 2ON W OF 85W...AND POSSIBLE 
ISOLATED SHOWERS ALONG THE FRONT AXIS E OF 85W. NORTHERLY WINDS 
UP TO 20 KT ARE NOTED BEHIND THE FRONT. MARINE OBS ELSEWHERE 
ACROSS THE CARIBBEAN SHOW 5-15 KT WINDS FROM THE NE. THIS FLOW 
IS BRINGING LOW LEVEL MOISTURE INTO THE CARIBBEAN FROM THE 
ATLANTIC OCEAN...ENHANCING SOME CLUSTERS OF WEAK SCATTERED 
SHOWERS.

ATLANTIC OCEAN... 
A DEEP LAYERED TROUGH CONTINUES TO SLOWLY MOVE OFF THE CONUS 
SEABOARD SUPPORTING A COLD FRONT THAT ENTERS THE W ATLC REGION 
ALONG 32N72W AND EXTENDS SW TO ACROSS CENTRAL CUBA ALONG 26N75W 
22N79W. THIS FRONT IS GENERATING SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS WITHIN 40 NM AHEAD OF IT. THIS FRONT IS EXPECTED 
TO CONTINUE TO TRACK EASTWARD WITH CONVECTION OVER THE NEXT 24 
HOURS. FARTHER EAST INTO THE CENTRAL ATLC...AN UPPER LEVEL 
CUT-OFF LOW IS NEAR 26N48W SUPPORTING A 1015 MB SURFACE LOW NEAR 
THE SAME LOCATION. A SURFACE TROUGH IS ANALYZED FROM 30N55W TO 
THE LOW CENTER...THEN CONTINUES SSW ALONG 23N45W TO NEAR 17N52W. 
SCATTERED SHOWERS ARE WITHIN 20 NM ON EITHER SIDE OF THE AXIS S 
OF 24N. SIMILAR CONVECTION ALONG WITH ISOLATED THUNDERSTORMS 
SURROUND THE LOW LEVEL CENTER FROM 24N-30N BETWEEN 38W-48W. GALE 
FORCE WINDS ARE NOTED N OF 29N BETWEEN 45W AND 50W GENERATING 
SEAS 15 TO 18 FT. THIS SYSTEM IS EXPECTED TO CONTINUE TO WEAKEN 
OVER THE NEXT 24 HOURS. RELATIVELY FAIR WEATHER CONDITIONS ARE 
ELSEWHERE ACROSS THE OCEAN.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA/MONTALVO